Cigarettes and other smoking articles produce an aerosol, smoke in the case of cigarettes, which is inhaled by a user. Filters for smoking articles are used to modify the aerosol before it reaches the user's mouth. Filters known in the art for this purpose may be formed from a plug of fibrous cellulose acetate or other materials with similar physical properties.
To enhance the removal of certain smoke constituents various additives may be added to smoking article filters. Examples include smoke adsorbents such as activated carbon which adsorbs certain smoke constituents thus removing them from the smoke stream passing through the filter. In addition to removing constituents from smoke, filter additives may impart characteristics to smoke or other aerosols passing through the filter. For example, fragrances and flavourants may be incorporated into the filter which alter the aroma and taste characteristics of the aerosol.